Sound-reproducing instrument.



H. E. BALLARD. soUND REPBODUGING INSTRUMENT.

APPLICATION FILED JULYB, 1908. 985,496, Patented Feb. 28, 1911.

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HABLAN H. BLLARD, OF'PITTSFIELD, -MASSACHUSETTS.

SOUND-BEPRODUGING INSTRUMENT.

i Specification of Letters Patent.

Patented Feb. 28, 1911.

Application led. .Tuly 6, 1908. Serial No. 442,781.

-sound reproducing instruments, but more particularly to sound boxes for phonographs, graphophones, and the like. The

greatest problem in the construction of these instruments has been to eliminate the metallic sounds caused by the contact of the stylus holder with the metallic portions of the vibrations of the stylus to be transmitted to the diaphragm holder, and produces the metallic sounds so common to instruments of this type.

In the present invention, this metallic contact has been 'avoided by means of vibration insulation separating the metallic parts.

One feature of the' invention is the simplicity of construction. In place of spring arms with complicated adjusting screws and locknuts, as has heretofore been used, a cushion of resi-lient material has been placed between the stylus holding bar and the rim ofthe diaphragm holder. This allows free vibration of the stylus holder, but does not transmit -the vibration to the box, as is the case with the steel springs now used. This bar is preferably fastened to the rim of the diaphragm holder by means complete.

of set screws passing through aperturesV in the bar. These apertures are preferably of a considerably greater diameter than that of the screws to allow free vibration of the bar and prevent metallic contact.

Another feature is the form of the cushion mentioned above. This is preferably wedge shaped sothat it acts as a means for tilting, or regulating the lever which transmits the vibrations from the stylus holding bar to the diaphragm.

Heretofore, the diaphragm has been held between two washers within the diaphra holder, but constant use has caused 1t to shde between these washers and come in contact with the inside walls of the holder. To prevent this, a vibration insulating rim may be placed about thediaphragm, as will b e described more fully hereinafter. In the instruments in use at present, the contact point of the vibration transmitting vlever has generally been fastened to the center of" the diaphragm, as this lever has been constructed of rigid material. This connection is the cause of great inconvenience, as the movement of the lever tears the diaphragm and causes false sounds.

A feature of the invention is a resilient .lever which does not require fastening to the diaphragm, as it will follow the motions of the latter, and keep constant contact when properly adjusted.

Another feature is a resilient tip or contact 'point upon the lever which transmits to the diaphragm a more even tone than is produced by solid tip.

Alever which does not require attachment to the diaphragm allows the use of a great variety of materials in the construction of the 4latter as great strength is not required. Heretofore, it has been found necessary to use mica for diaphragms, as this was the only material of sufficient resiliency which could at all stand the strain. With the resilient lever or tip, paper, ivory, celluloid, parchment, or a large number of other materials, might be utilizedV which would g1ve as good, if not better results, at a less cost.

It should be clearly understood that the invention is notl limited to the construction and arrangement of parts herein described, as they may be materially varied without altering the invention.

One embodiment oft-he invention is shown in the accompanying drawings in which Figure 1, is a top view of the sound box Fig. 2, a section on 2--2 of Fig. 1. Fig. 8, a section on 3 3 of Fig. 2, with all parts above the section removed.

In the drawings, the diaphragm 4 is held in the sound box 5 by the diaphragm holder 6 which is fastened to the latter by means of screws 7 Upon the rim 8 of the diaphragm holder 6 is fastened the stylus carrying bar 9by means of the thumb screws 10. Be-

tween this bar 9 and the rim 8, is insertedA erably wedge shaped with the narrow edge Y toward the top of the box 5, as is shown in Fig. 2, and acts as an adjusting means for lever 12, which carries the vibrations from thebar 9 -to the face of the diaphragm 4.

The stylus carrying bar 9 is provided with apertures 13 and 14 to allow the thumb Screws 10 to pass through them, and mesh in the tapped holes 15 and 16 respectively. These apertures 13 and 14 are preferably cut with their diameter considerably larger than that of the thumb screws 10, so that the latter may not come in contact with the walls of the former. Also these large apertures allow the tilting of the bar 9 to adjust the lever 12, 'as will b e described hereinafter. y

Upon the bar 9 is the st lus holder 17 having 'an aperture 18 inw ich thestylus 19 is seated, the latterbeing h'eld in place by means of the set screw 20. To the pro jection or 'ear 2V1 on the bar 9, is fastened the lever 12.. This lever has a contact point 22 whic h may be fastened -torthe diaphragm '4, or may rest upon it. It may be ofany suitable ,.construction, but4 an advantageous type is shown inthe drawings in which/a shaiik 23, attached to the `ear 21, supports a crook 24, having at its end the contact point 22. The whole is preferably composed of flat watch spring steel or other resilient material, sothat the contactV point may fol also move longitudinally with the s ank of .the lever. This prevents any tendency of i the contact point to Vdamage the diaphragm.

-The diaphragm is held within`the diaphragm. holder 6 by the washers 25an`d' 26,

A"and may be fitted with a washer or rim 27,

preferably constructed of vibration-absorption material, about its circumference. This prevents. the diaphragm from slidingI between the washers,25 and 26,' and coming in Contact withthe metal inner wall of the holder 6.

Between the heads ofthe thumb` screws a sound box, a diaphragm -within said box,

or other suitable material, so that the latterv lholds the former more firmly, and revents the communication of the vibration om the bar 9 to the diaphr'a The method of adJustment of the lever 12- is as follows :-f-If itis desired -to' vcausethe4 'contact point to "be pressed more firmly` 'against the dia hragm, tlie thumb screwsholder.

10 are advance causing the heads 29- to press against the bar 9. As this bar issu'pported by the wedge shaped cushion 11, a

ressure upon the former causes it to tilt orward, as the thick portion of the cushion offers greater lresistancethan the thin portion.' This tilting causes the-contact point l22 to be pressed against the diaphragm. Ifj

. the thumb screws are loosened, the contact point will be'withdrawn in the same manner. Thus it will be seen that the'thumb free to rock upon'the cushion.

screws act as a means v.of fastening'the stylus carrying bar 9 to the diaphragm holder 6,

and as an adjusting means for the lever 12. Y

A resilient tip ma .be placed upon'the contact point 22 of t e lever 12.v Where a resilient tip or a spring lever is used, it is unnecessary 'to fasten the lever of the diaphragm, thus allowingl greater freedom of action, and causing the instrument to produce sounds which would be too delicate to operate the ordinary type of diaphragm.

VhatI 'claim as my invention and desir to secure by Letters Patent is 1. In an instrument for producing sound,

a sound box, a diaphragm within vsaid sou nd box, a stylus, a stylus carrier mounted upon the outside of said box, and insulating means between said stylus carrier and said box.

2. In an instrument for producing sound,

a sound box, a diaphragm within said box,

a stylus carrier movably mounted upon-the outside of said box, and an insulating cushion betweenv said stylus carrier and said box.

3. In aminStrument for producing sound, a sound box, a diaphragm within" said box, a stylus carrier movabl y'mounted upon the outside of said box, an an insulating cushent material betweensaid stylus carrier andsaid box, aiid means for attaching said carrier to said box whereby the carrier shall be 5. vIn an instrument forproducing'sound,

a sound box, a diaphragm within vsaid box, a stylus, a styluscarrier, means for connecting said carrier with said diaphragm, a

a stylus a styluscarrier, a cushion-of resilient material between saidstylus' carrier and said box, and screws pass through apertures in -said carrier tov attac said carrier to said box.

ywedge shaped cushion betweemsaid carrier- -iio ' 7. In an'instrument for producing sound,

a stylu's,a stylus carrier, a lever carried .b said stylus carrier to connect the same wit said diaphragm, a cushion of resilient vmatures in sai saidbox. v 8. In' an instrumentfor producing sound,

a sound box, a diaphragm within said box,

a sound box, a ldiaphragmwithin said box,

a stylus, astylus carrier, a lever carried by 'i said stylus carrier to connect the same with said diaphragm, a cushion ofresilient madterial between said stylus carrier and said box, and screws passing through `apertures y in said carrier to fasten the same to said box,

said apertures being of a greater diameter than the screws to allow the carrier to rock upon the cushion.

9. In an instrument for producing sound, a sound box', a diaphragm Within said box, a stylus, a stylus carrier, means for connecting said carrier with said diaphragm, 'a wedge `shaped cushion of resilient material between said carrier and said box, and adjusting screws to fasten said carrier to said box whereby said carrier may rock upon said cushion.-

10. n :u1/instrument for producing sound.

a sound box, a diaphragm within said box,

a stylus, a stylus carrier, a lever carried by said stylus carrier to connect the same with Sald dmphraonl, a cushion o' resilient insulating materlal between szucl stylus carrier and said box, und screws passing throughapertures in said carrier to fasten the same to said box, Saul screws bolug insulated from sald carrler.

In testimony wherof I ufix my signature 25 

